package com.itttq.gshop.generic.cmpt;

import java.io.IOException;
import java.io.PrintWriter;
import java.lang.reflect.Method;
import java.lang.reflect.Type;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.itttq.gshop.domain.to.ResultTo;
import com.itttq.gshop.generic.cmpt.annotation.Auth;
import com.itttq.gshop.generic.controller.GenericController;
import com.itttq.gshop.generic.util.Constants;
@Component
public class LoginInterceptor extends GenericController implements
		HandlerInterceptor {
	private static final long serialVersionUID = -4308107581849196383L;

	public LoginInterceptor() {}

	/**
	 * 在业务处理器处理请求之前被调用 如果返回false 从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链
	 *
	 * 如果返回true 执行下一个拦截器,直到所有的拦截器都执行完毕 再执行被拦截的Controller 然后进入拦截器链,
	 * 从最后一个拦截器往回执行所有的postHandle() 接着再从最后一个拦截器往回执行所有的afterCompletion()
	 */
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
		String url = request.getRequestURL().toString();
		final HandlerMethod handlerMethod = (HandlerMethod) handler;
        final Method method = handlerMethod.getMethod();
        final Class<?> clazz = method.getDeclaringClass();
        final Type returnType = method.getGenericReturnType();
        Auth auth = null;
        if (clazz.isAnnotationPresent(Auth.class)) auth = clazz.getAnnotation(Auth.class);
        if (method.isAnnotationPresent(Auth.class)) auth = method.getAnnotation(Auth.class);
        
        if(null == auth) return true;
        for(String excl : auth.excls()) {
        	if(excl.equals(method.getName())) {
        		return true;
        	}
        }
    	
		Object obj = this.getSession(request, Constants.SESSION_USER);
		if (null == obj) {
			// 判断是不是ajax请求。只要返回类型不是ModelAndView的都是ajax请求
			if(returnType.getTypeName().contains("ModelAndView")) {
				// 记录本次地址，作为登录后跳转的目标地址
				this.setSession(request, Constants.SESSION_URL_LAST, url);
				request.getRequestDispatcher("/login.html").forward(request, response);
			} else {
				// 记录请求的来源地址
				this.setSession(request, Constants.SESSION_URL_LAST, request.getHeader("Referer"));
				// 返回指定的值
				PrintWriter out = null;
			    try {
			        out = response.getWriter();
			        out.append("{\"code\":" + ResultTo.USER_NOT_LOGIN + ", \"msg\":\"请先登录！\"}");
			    } catch (IOException e) {
			        e.printStackTrace();
			    } finally {
			        if (out != null) {
			            out.close();
			        }
			    }
			}
			return false;
		}
        
		return true;
	}

	// 在业务处理器处理请求执行完成后,生成视图之前执行的动作
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {
	}

	/**
	 * 在DispatcherServlet完全处理完请求后被调用
	 *
	 * 当有拦截器抛出异常时,会从当前拦截器往回执行所有的拦截器的afterCompletion()
	 */
	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
			throws Exception {
	}
}
